Monthly normals (averages) for the period 1971 to 2000 from the National Climatic Data Center (NCDC) or calculated from daily time series were the source for calculating daily normal values. For probabilities of occurrence and conditional mean values (e.g. of 'measurable' values) no NCDC versions were available, so those values were calculated by the Minnesota State Climatology Office. The technique of interpolating monthly normal to daily values follows the recommendations of NCDC; raw daily normals tend to have variations which are not necessarily statistically significant (short term variations are as likely to be random variations as 'real' climate features).
Target location (used to sort station list by distance) is [not set]